In vitro antimicrobial potential of organic solvent extracts of novel actinomycetes isolated from forest soil

In vitro screening of antibacterial and antifungal activities of hexane, chloroform, ethyl acetate, methanol and water extracts of selected promising actinomycetes strains were studied towards Gram-positive, Gram-negative bacteria, dermatophytes and opportunistic pathogens. Crude antimicrobial metabolites were extracted by liquid-liquid extraction and solid-liquid extraction method using hexane, chloroform, ethyl acetate and methanol. The lowest minimum inhibitory concentration (MIC) of the extracts was assessed by the broth micro dilution method. All the extracts obtained from eight strains showed promising activity against tested Gram-positive bacteria. The hexane extracts of strain ERI-1 exhibited activity against Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis at a concentration of 5 mg/ml. Ethyl acetate extract of strain ERI-4 showed MIC of 5 mg/ml but S. epidermidis and S. aureus. B. subtilis exhibited activity at 2.5 mg/ml. However, ethyl acetate and lyophilized water extract of strain ERI-3 inhibited the growth of Trichophyton mentagrophytes, Trichophyton rubrum, Epidermophyton floccosum and Scropulariopsis sp at 10 mg/ml. Overall significant antibacterial and antifungal activities were noted in the ethyl acetate extract of ERI-1 and ERI-3. Methanol extract of ERI-26 exhibited good antibacterial and antifungal activities.Keywords: Actinomycetes, organic extracts, minimum inhibitory concentration (MIC), antimicrobial activityAfrican Journal of Biotechnology, Vol 13(18), 1891-189

Des-A-lupane in an East African lake sedimentary record as a new proxy for the stable carbon isotopic composition of C₃ plants

We studied the high-resolution and well-dated 25,000 year sedimentary record of Lake Challa, a deeptropical crater lake in equatorial East Africa, to explore new proxies for paleoenvironmental and paleohydrologicalchange. Sedimentary biomarker analysis revealed the presence of des-A-triterpenoids witholeanane, ursane and lupane carbon skeletons, microbial degradation products of angiosperm planttriterpenoids. Their increased influx from 16,000 years ago corresponds with previously documentedchanges in the terrestrial vegetation of the Lake Challa basin during postglacial warming, in particularthe relative increase in C3/C4 plant ratio inferred from the stable carbon isotopic signature (d13C) of sedimentaryn-alkanes derived from plant leaf waxes. In contrast to this n-alkane d13C signature, the d13C ofdes-A-lupane maintains a constant value of ?27.4 ± 1.1‰ across the glacial–interglacial transition. Sincedes-A-lupane is derived from C3 plants, its d13C signature is here proposed to represent a novel and independentproxy for the time-variable carbon isotopic composition of local terrestrial C3 plants, which canimprove estimates of the C3/C4 plant ratio based on two-end member mixing models of n-alkane d13Cvalues.

Growth Performance, Organ Weights and Some Blood Parameters of Replacement Laying Pullets Fed with Increasing Levels of Wheat Bran

ABSTRACTThis study was conducted to determine the growth performance, organ weights, and selected blood parameters of replacement laying pullets (development phase) fed increasing levels of wheat bran (WB). A total of 240 70-d-old White Leghorn pullets (Hybrid L33) were evaluated for seven weeks. Birds were assigned to three dietary treatments according to a completely randomized design. Treatments consisted of diets containing 100 (T1), 150 (T2), or 200 g/kg (T3) of WB in partial replacement of corn, with 10 replicates per treatment of eight birds per replicate. Birds fed T2 presented higher body weight (p<0.05) compared with T1 and T3 (1112.52 to 1163.35 g). Also, T2 birds presented higher methionine plus cystine intake relative to T1 (0.38 to 0.40 g/bird/day). Likewise, a higher inclusion of WB (200 g/kg) increased crude fiber (2.29 to 2.63 g/bird/day) and crude fat (1.98 to 3.58 g/bird/day) intakes (p<0.05). However, the experimental treatments did not affect the relative weight of the organs or small intestine and cecum length (p>0.05). Serum concentration of triacylglycerols, cholesterol, calcium, phosphorus, hematocrit, or hemoglobin levels were not significantly different (p>0.05) among treatments. These findings indicate a beneficial effect of use of 150 g/kg of wheat bran on the growth performance of pullets during the development phase; however, the inclusion of this cereal up to 200 g/kg had no effect on organ weights and blood parameters

Molecular characterization of glucosinolates and carotenoid biosynthetic genes in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

The present study aimed to investigate the contents of glucosinolates (GSLs) and carotenoids in eleven varieties of Chinese cabbage in relation to the expression level of the important transcription factors. MS and HPLC analysis identified the presence of 13 GSLs (progoitrin, sinigrin, glucoalyssin, gluconapoleiferin, gluconapin, glucocochlearin, glucobrassicanapin, glucoerucin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, neoglucobrassicin and gluconasturtiin) and four carotenoids (lutein, zeaxanthin, α-carotene and β-carotene). GSL contents were varied among the different cabbage varieties. The total GSL content ranged from 2.7 to 57.88 μmol/g DW. The proportion of gluconapin (54%) and glucobrassicanapin (22%) was higher in all the varieties, respectively. Results documented the variation in total and individual carotenoid contents that have also been observed among different varieties; however, the total carotenoid contents ranged from 289.12 to 1001.41 mg kg−1 DW (mean 467.66). Interestingly, the proportion of lutein (66.5) and β-carotene (25.9) were higher than α-carotene (5.1) and zeaxanthin (2.5%). Consequently, the expression level of the regulatory gene, MYB28 was higher in ‘K0648’ and was directly proportional to GSL content. Similarly, the expression levels of 1-PSY were higher in ‘K0112’; however, the expression levels of 2-ZDS, 3-LCYB, 4-LCYE, 5-CHXB and 7-NCED genes showed no significant difference. In addition, the correlation between GSL and carotenoid contents and gene expression level showed moderate significant difference in each Chinese cabbage

Molecular characterization of glucosinolates and carotenoid biosynthetic genes in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

AbstractThe present study aimed to investigate the contents of glucosinolates (GSLs) and carotenoids in eleven varieties of Chinese cabbage in relation to the expression level of the important transcription factors. MS and HPLC analysis identified the presence of 13 GSLs (progoitrin, sinigrin, glucoalyssin, gluconapoleiferin, gluconapin, glucocochlearin, glucobrassicanapin, glucoerucin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, neoglucobrassicin and gluconasturtiin) and four carotenoids (lutein, zeaxanthin, α-carotene and β-carotene). GSL contents were varied among the different cabbage varieties. The total GSL content ranged from 2.7 to 57.88μmol/gDW. The proportion of gluconapin (54%) and glucobrassicanapin (22%) was higher in all the varieties, respectively. Results documented the variation in total and individual carotenoid contents that have also been observed among different varieties; however, the total carotenoid contents ranged from 289.12 to 1001.41mgkg−1DW (mean 467.66). Interestingly, the proportion of lutein (66.5) and β-carotene (25.9) were higher than α-carotene (5.1) and zeaxanthin (2.5%). Consequently, the expression level of the regulatory gene, MYB28 was higher in ‘K0648’ and was directly proportional to GSL content. Similarly, the expression levels of 1-PSY were higher in ‘K0112’; however, the expression levels of 2-ZDS, 3-LCYB, 4-LCYE, 5-CHXB and 7-NCED genes showed no significant difference. In addition, the correlation between GSL and carotenoid contents and gene expression level showed moderate significant difference in each Chinese cabbage